Refactor assignment.

New version is much more elegant and probably slower. Uses
library functions implemented in jq rather than dedicated opcodes.

builtin.c

@@ -552,6 +552,9 @@ static const char* jq_builtins[] = {
   "def max_by(f): _max_by_impl(map([f]));",
   "def min_by(f): _min_by_impl(map([f]));",
   "def del(f): delpaths([path(f)]);",
+  "def _assign(paths; value): value as $v | fold . as $obj (path(paths) as $p | $obj | setpath($p; $v));",
+  "def _modify(paths; update): fold . as $obj (path(paths) as $p | $obj | setpath($p; getpath($p) | update));",
+  
 };
 
 

compile.c

@@ -317,22 +317,6 @@ block gen_fold(const char* varname, block init, block fold) {
                           OP_HAS_VARIABLE));
 }
 
-block gen_assign(block expr) {
-  block result_var = block_bind(gen_op_var_unbound(STOREV, "result"),
-                                gen_noop(), OP_HAS_VARIABLE);
-
-  block loop = BLOCK(gen_op_simple(DUP),
-                     expr,
-                     gen_op_var_bound(ASSIGN, result_var),
-                     gen_op_simple(BACKTRACK));
-
-  return BLOCK(gen_op_simple(DUP),
-               result_var,
-               gen_op_target(FORK, loop),
-               loop,
-               gen_op_var_bound(LOADV, result_var));
-}
-
 block gen_definedor(block a, block b) {
   // var found := false
   block found_var = block_bind(gen_op_var_unbound(STOREV, "found"),

compile.h

@@ -34,7 +34,6 @@ block gen_subexp(block a);
 block gen_both(block a, block b);
 block gen_collect(block expr);
 block gen_fold(const char* varname, block init, block body);
-block gen_assign(block expr);
 block gen_definedor(block a, block b);
 block gen_condbranch(block iftrue, block iffalse);
 block gen_and(block a, block b);

execute.c

@@ -298,34 +298,6 @@ jv jq_next() {
       break;
     }
 
-    case ASSIGN: {
-      stackval replacement = stack_pop();
-      stackval path_end = stack_pop();
-      stackval path_start = stack_pop();
-      jv_free(path_end.value);
-      jv_free(path_start.value);
-
-      jv path = jv_array();
-      for (int i=path_start.pathidx; i<path_end.pathidx; i++) {
-        path = jv_array_set(path, i, jv_copy(pathbuf[i]));
-      }
-
-
-
-      uint16_t level = *pc++;
-      uint16_t v = *pc++;
-      frame_ptr fp = frame_get_level(&frame_stk, frame_current(&frame_stk), level);
-      jv* var = frame_local_var(fp, v);
-      jv result = jv_setpath(*var, path, replacement.value);
-      if (jv_is_valid(result)) {
-        *var = result;
-      } else {
-        print_error(result);
-        *var = jv_null();
-      }
-      break;
-    }
-
     case INDEX: {
       stackval t = stack_pop();
       jv k = stack_pop().value;

opcode_list.h

@@ -16,7 +16,6 @@ OP(APPEND, NONE,    2, 1)
 OP(INSERT, NONE,    4, 2)
 
 OP(GETPATH, NONE,   2, 1)
-OP(ASSIGN, VARIABLE, 3, 0)
 
 OP(CALL_BUILTIN, CFUNC, -1, 1)
 

parser.y

@@ -164,11 +164,16 @@ static block gen_format(block a, jv fmt) {
   return BLOCK(a, gen_call("format", BLOCK(gen_lambda(gen_const(fmt)))));
 }
  
-static block gen_update(block a, block op, int optype) {
-  if (optype) {
-    op = gen_binop(gen_noop(), op, optype);
-  }
-  return gen_assign(BLOCK(a, gen_op_simple(DUP), op));
+static block gen_update(block object, block val, int optype) {
+  block tmp = block_bind(gen_op_var_unbound(STOREV, "tmp"),
+                         gen_noop(), OP_HAS_VARIABLE);
+  return BLOCK(gen_op_simple(DUP),
+               val,
+               tmp,
+               gen_call("_modify", BLOCK(gen_lambda(object), 
+                                         gen_lambda(gen_binop(gen_noop(),
+                                                              gen_op_var_bound(LOADV, tmp),
+                                                              optype)))));
 }
 
 %}
@@ -216,7 +221,7 @@ Term "as" '$' IDENT '|' Exp {
 } |
 
 Exp '=' Exp {
-  $$ = gen_assign(BLOCK(gen_op_simple(DUP), $3, gen_op_simple(SWAP), $1, gen_op_simple(SWAP)));
+  $$ = gen_call("_assign", BLOCK(gen_lambda($1), gen_lambda($3)));
 } |
 
 Exp "or" Exp {
@@ -236,7 +241,7 @@ Exp "//=" Exp {
 } |
 
 Exp "|=" Exp {
-  $$ = gen_update($1, $3, 0);
+  $$ = gen_call("_modify", BLOCK(gen_lambda($1), gen_lambda($3)));
 } |
 
 Exp '|' Exp { 

testdata

@@ -411,6 +411,10 @@ null
 [-1,1,3]
 [0.5, 1.5, 2.5]
 
+.foo += .foo
+{"foo":2}
+{"foo":4}
+
 .[0].a |= {"old":., "new":(.+1)}
 [{"a":1,"b":2}]
 [{"a":{"old":1, "new":2},"b":2}]